Method and apparatus for calibrating display devices and automatically compensating for loss in their efficiency over time
US6414661B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 5, 2000 |
| Grant date | Jul 2, 2002 |
| Priority date | — |
| Expiry date | Aug 27, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2360/145
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and associated system that compensates for long-term variations in the light-emitting efficiency of individual organic light emitting diodes (OLEDs) in an OLED display device, calculates and predicts the decay in light output efficiency of each pixel based on the accumulated drive current applied to the pixel and derives a correction coefficient that is applied to the next drive current for each pixel. In one exemplary embodiment of the invention, the calculation is based the accumulated current that has been passed through the device. In another exemplary embodiment, the calculation is based on a difference in voltage across the pixel at two instants. The compensation system is best used after the display device has been calibrated to provide uniform light output. The present invention further provides a method for calibrating a display device comprising an array of individually adjustable discrete light emitting devices (pixels) using a camera having an array of radiation sensors or a single photodetector. According to this method, the camera captures respective images of substantially equal-sized first sub-areas and adjusts the driving current for each of said pixels wi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.